Home Cell Phone News Articles Resources Directory Site Map
3G Technology


PDA Cell Phones

Camera Cell Phones


10 Questions About Cellular Phones Answered
  1. What's the difference between analog and digital phones?
  2. What is a Dual Band Phone?
  3. What type of battery has the longest life?
  4. What's the difference between the Stand-by time and Talk time?
  5. What is a roaming charge?
  6. What are peak and off peak hours?
  7. What are anytime minutes?
  8. Do I pay for the call when someone calls me?
  9. Should I buy a cell phone or look for a free cellular phone?
  10. What to do if you want to upgrade/downgrade or cancel your service plan?
[ Read the Entire Article ]


NTP Security Authentication and Trusted Time References

NTP (Network Time Protocol) synchronises networks to a single time source using timestamps to represent the current time of the day, this is essential for time sensitive transactions and many system applications such as email. NTP is therefore vulnerable to security threats, whether from a malicious hacker who wants to alter the timestamp to commit fraud or a DDoS attack (Distributed Denial of Service - normally caused by malicious malware that floods a server with traffic) that blocks server access. However, being one of the Internet's oldest protocols and having been developed for over 25 years, NTP is equipped with its own security measures in the form of authentication.

Authentication verifies that each timestamp has come from the intended time reference by analysing a set of agreed encryption keys that are sent along with the time information. NTP, using Message Digest encryption (MD5) to un-encrypt the key, analyses it and confirms whether it has come from the trusted time source by verifying it against a set of trusted keys. Trusted authentication keys are listed in the NTP server configuration file (ntp.conf) and are normally stored in the ntp.

keys file. The key file is normally very large but trusted keys tell the NTP server which set of subset of keys is currently active and which are not. Different subsets can be activated without editing the ntp.keys file using the trusted-keys config command. Authentication is therefore highly important in protecting a NTP server from malicious attack; however there are many time references were authentication can't be trusted. Microsoft, who has installed a version of NTP in their operating systems since Windows 2000, strongly recommends that a hardware source is used as a timing reference as Internet sources can't be authenticated.

NTP is vital in keeping networks synchronised but equally important is keeping systems secure. Whilst network administrators spend thousands in anti-viral/malware software many fail to spot the vulnerability in their time servers. Many network administrators still entrust Internet sources for their time reference. Whilst many do provide a good source for UTC time (Coordinated Universal Time - the international standard of time), such as nist.

gov, the lack of authentication means the network is open to abuse. Other sources of UTC time are more secure and can be utilized with relatively low cost equipment. The easiest method is to use a specialist NTP GPS time server that can connect to a GPS antenna and receive an authenticated timestamp by satellite. GPS time servers can provide accuracy to UTC time to within a few nanoseconds as long as the antenna has a good view of the sky. They are relatively cheap and the signal is authenticated providing a secure time reference. Alternatively there are several national broadcasts that transmit a time reference.

In the UK this is broadcast by the National Physics Laboratory (NPL) in Cumbria. Similar systems operate in Germany, France and the US. Whilst this signal is authenticated, these radio transmissions are vulnerable to interference and have a finite range. Authentication for NTP has been developed to prevent malicious tampering with system synchronisation just as firewalls have been developed to protect networks from attack but as with any system of security it only works if it is utilised.

Copyright (c) 2008 Richard Williams.

Richard N Williams is a technical author and a specialist in the telecommunications and network time synchronisation industry helping to develop dedicated time server products. Please visit us for more information about a GPS time server or other NTP products.

Mobile Phones

Best Registry Cleaner There isnt One - If you are thinking finding the Best Registry Cleaner, think again.

Protect your application with Oracle Data Guard - Framing a Disaster Recovery mechanism for your Oracle database may seem to be a nightmare, but Oracle Data Guard is a straightforward solution to this problem.

The importance of using personal scales - There are many current situations where the weight of an object or person needs to be accurately determined.

Satellite TV on PC Get satellite TV on your PC - Whether you prefer to watch satellite TV for PC rather than the usual cable TV, it is all a matter of subjective choice because both are known to have specific strengths as well as weaknesses that you would need to consider before you finalize.

VoIP Communication Technology - VoIP.

DontWorryCommunications.com © Copyright 2023, All Rights Reserved.